Surrounded by supporters, including Democratic elected officials from across Queens and members of various labor unions, John Liu officially announced his candidacy for State Senate.

Liu will be challenging State Senator Tony Avella, a fellow Democrat and former colleague of Liu's in the City Council who angered party leaders recently when he announced that he would be joining the Independent Democratic Conference (IDC), a group of five Democratic state senators that caucus with the Republican minority in the legislature in a power-sharing agreement.

“I will be a collaborator,” Liu said Friday morning outside the Bayside LIRR stop, just a few blocks from Avella's district office. “Someone who will work closely with his colleagues. It requires a team effort.”

Liu referenced his opponent's move to join the IDC, which squandered a small majority the Democrats enjoyed in the legislative body and that Liu said betrayed the wishes of voters.

“The people of New York State elected Democrats to the majority of the State Senate, but there is a small number of people who are Democrats that are voting with the Republicans,” he said.

In response, Avella said his responsibility was to the voters in his district, not the Democratic Party.

“I work for the people I represent, not for the Queens party bosses or political insiders,” he said.

Liu said he expects Governor Andrew Cuomo to get involved in helping Democrats defeat members of the IDC. The group's leader, Bronx State Senator Jeff Klein, also has a Democratic challenger in Oliver Koppell.

“I expect the governor to be very active,” said Liu.

Liu left the post of comptroller to run for mayor last year. His campaign fizzled out after the Campaign Finance Board refused to issue millions of dollars in matching funds after a member of Liu's fundraising team was found guilty of accepting money from straw donors. Liu himself has not been charged with any wrongdoing.

Liu said that was in the past, despite a lawsuit he has filed against the board, and that he was looking for a fresh start.

“I don't hold any grudges,” he said. “I see this as yet another opportunity for me personally to join a body where I can officially represent and be a voice for this community.”

Liu labeled himself a “progressive Democrat” who would work for a real minimum wage and advance a package of legislation focused on women's equality.

“I will be a fighter and not shy about advancing cutting-edge proposals,” he said.

Avella said that he was proud of his record, and looks forward to defending in on the campaign trail.

“Whether it's helping our seniors, passing marriage equality, or protecting our environment, I have always fought for the issues that matter most to the people of my district,” he said. “I look forward to discussing my progressive record of accomplishment and debating the issues before the voters.”

Editor's Note: This article was updated on May 26 with comments from State Senator Tony Avella.